Safer to put D as 1 step below the baritone E
The A is possible as there are GCEA sets for baritone.
Another option is to put the baritone B string 1 step down as the first string. That will give you a "low reentrant" tuning since that A would be an octave low.
I haven't done it personally but I'm sure I've seen threads on it. You will probably have to cobble together a string set to get the proper tension for each string. The high A will be the tricky one. You will need a super thin one to get that high on baritone scale.
hmm, rule of thumb is that if it doesn't say "solid", it is almost certainly a laminate. Not saying that's bad, but if you're expecting K-brand (you know what I mean - *real* K-brand ;-) ) quality on this one, think again.